User Manual

AMPLIFIER CONTROLLER BOARD REV.5
PUB12-030 Rev. 1 Feb 14, 2013 12-030-11 Amplifier Controller Board Rev.5
3 SETUP PROCEDURES
The following sections detail the various set up procedures for the MXi transmitter system. These procedures
should only be done by qualified personnel. If the calibrations and setups are done improperly, it can result in the
transmitter being prone to damage.
The transmitter is normally set up in the factory for the particular operating power required when first installed. Set
up procedures would only be required if certain elements of the MXi transmitter had to be replaced or repaired
that would have affected the calibrations. An example of this would be the MXi amplifier controller board itself, the
output RF couplers, the RF cables or the +50V power supply.
If the output power is being changed, then some setup and calibration would be needed since the transmitter
would be set up for the previous RF power level. Caution: do not increase the power output of the MXi transmitter
beyond the original factory set level without first consulting LARCAN field service.
3.1 RF DETECTOR
The RF detector is normally calibrated at the factory or by LARCAN field personnel and should not require onsite
re-adjustments except in the following circumstances.
 The desired output power level of the transmitter is to be changed from the factory setting for a full 100%
power reading. Note that the operator should not just increase and readjust power beyond the
recommended rating of the transmitter without prior approval from LARCAN technical services.
 A replacement MXi amplifier control board or directional coupler has been installed in the transmitter.
This procedure assumes that the RF detector is being set-up with the transmitter connected to an RF modulator
input and output load (or antenna) that is the actual configuration it is intended to operate with.
3.1.1 Test Equipment Required
a) An RF power meter such as the HP 436A or similar. For analog transmitters, a BIRD through-line
wattmeter is sufficient.
b) A Spectrum Analyzer, HP 8558B or similar.
If the operator wishes to set up the unit on the bench, then a number of extra pieces of test equipment are
necessary.
 An RF generator/modulator that will replicate the desired signal and level
 An analog transmitter would need a video generator such as Tektronix 1900 or similar, and a
analog modulator and upconverter
 A digital transmitter would need the Pulse Modulator used with the transmitter.
 RF Load rated at the transmitter power and associated cable
3.1.2 Jumper Installation
If the transmitter is not being upgraded from Analog to Digital service (or vice versa), then there should be no
need to change the jumpers for the traps or gain. If there is a change, the trap jumpers would need to be modified
and perhaps the gain as well.
For Analog service, the color burst and aural carrier traps should normally be installed. The aural carrier traps for
E10 and E13 would be placed on the upper two pins
For the forward power sample, this would be jumpers E9 and E10.
For the reflected power sample, this would be jumpers E12 and E13.
For DVB Digital service, jumper E9 and E12 would not be installed, jumpers E10 and E13 would be installed in
DVB position.